Adjustable form holder system and method

ABSTRACT

An adjustable form holder, comprising a first bracket and a second bracket pivotally attached to each other by a hinge, so as to allow relative pivoting about a substantially vertical axis. The first and second brackets provide substantially vertical slots configured to receive an end of an elongate concrete form member. The hinge allows the concrete form members to be held in place on-edge at a selected horizontal angle relative to each other. The hinge may include a central aperture for receiving a form stake. Multiple form holders may be stacked for forming walls.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to concrete formwork and related devices. More particularly, the present invention relates to an adjustable form holder system that allows rapid interconnection of form members and is adjustable to a wide range of angles.

[0003] 2. Related Art

[0004] Designing, fabricating, and assembling formwork can be one of the most time-consuming tasks associated with concrete construction. Even simple jobs generally require the custom construction of forms to both conform to the surrounding landscape or other parts of the construction, and to provide for the desired shape for the finished product. Then, once the concrete is placed and cured sufficiently, the forms must be stripped and removed.

[0005] Unfortunately, the process of constructing and then stripping concrete forms results in a lot of waste, especially if the forms comprise wood boards or panels. Nailing the forms together, then removing the nails afterward, tends to damage the wood and limit its reusability. Similarly, repeated contact with wet concrete and weather conditions gradually damages the wood beyond the point of usefulness. The result is that the time, effort, and expense of constructing the formwork seems largely wasted.

[0006] There are a number of concrete form systems that are intended to speed up the process and provide a larger proportion of reusable members. Some of these involve ingenius frame, panel, and interlocking members that are reusable and have a longer life. However, many of these systems are complicated and expensive, and somewhat inflexible, too. In many cases, because of the large number of parts that must be connected, the time saved using these form systems does not justify their greater expense, except in very specific circumstances. However, such form systems are somewhat inflexible because they cannot fully anticipate the broad range of variations in shape and size needed in concrete formwork. Moreover, such extravagant systems may not be needed for formwork such as for building footings and the like, where the final appearance of the concrete is not particularly crucial because it will be buried.

SUMMARY OF THE INVENTION

[0007] It has been recognized that it would be advantageous to develop a concrete form system that allows rapid interconnection of form members.

[0008] It would also be desirable to have a concrete form system that is adjustable to a variety of configurations.

[0009] It would also be desirable to have a concrete form system that can speed-up the process of placing formwork, but that is simple and inexpensive.

[0010] The invention advantageously provides an adjustable form holder, comprising a first bracket and a second bracket pivotally attached to each other, so as to allow relative pivoting about a substantially vertical axis. The first and second brackets are substantially vertical slots configured to receive an end of an elongate concrete form member. The adjustable holder allows the concrete form members to be held in place on-edge at a selected horizontal angle relative to each other.

[0011] In accordance with a more detailed aspect of the present invention, the brackets are pivotally attached by a hinge having a cylindrical opening, allowing a form stake to be inserted therethrough for securing the form holder to the ground or some other structure.

[0012] In accordance with another more detailed aspect of the invention, the top and bottom of the hinge includes mating recesses to allow multiple form holders to be stacked atop each other for forming walls.

[0013] In accordance with another aspect thereof, the invention provides a concrete form system, comprising a plurality of adjustable form holders, and a plurality of elongate form members having ends disposed in the form holders, so as to form an enclosure for receiving concrete.

[0014] Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a perspective view of one embodiment of an adjustable form holder in accordance the present invention.

[0016]FIG. 2 is a plan view of the adjustable form holder of FIG. 1.

[0017]FIG. 3 is a plan view of an adjustable form holder having relatively narrow brackets compared to the diameter of the hinge.

[0018]FIG. 4 is a perspective view of a tall adjustable form holder according to the present invention.

[0019]FIG. 5 is a perspective view of two stacked form holders for forming a wall.

[0020]FIG. 6 is a perspective view of a portion of a form system in accordance with the present invention installed in place.

[0021]FIG. 7 is a perspective view of an alternative embodiment of a form holder wherein the brackets are removable from the hinge member.

[0022]FIG. 8A is a perspective view of an alternative embodiment of a form holder wherein the brackets are removably attachable to the form stake.

[0023]FIG. 8B is a cross-sectional view of the form stake of FIG. 8A.

[0024]FIG. 9 is a perspective view of an alternative embodiment of a form holder wherein the form stake comprises the hinge pin.

[0025]FIG. 10A is a perspective view of an alternative form stake having an attachment ring for removably receiving the brackets.

[0026]FIG. 10B is a combination cross-sectional and side view of the form stake of FIG. 10A and a bracket configured to connect thereto.

DETAILED DESCRIPTION

[0027] Reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Alterations and further modifications of the inventive features illustrated herein, and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.

[0028] Viewing FIGS. 1 and 2, in one embodiment the invention provides an adjustable form holder 10 comprising a first bracket 12, a second bracket 14, and a center hinge 16 that pivotally connects the two brackets. The brackets generally comprise a vertical pocket or slot, having side panels 18, a bottom panel 20, and a back end panel 22. These panels define a generally vertical slot 24 that is configured to receive an end of an elongate concrete form member 26, typically on-edge. The brackets may also include a mechanism for attaching or securing the elongate form member to the bracket once inserted. For example, as shown in the figures, the side panels of the slot may include holes 28 for the insertion of nails, bolts, or other fasteners for securing the form member in the slot. Alternatively, the brackets could be provided with other securing mechanisms, such as clamps,

[0029] The vertical slot 24 may be configured in a wide variety of sizes or shapes to accommodate any desired form member 26. As shown in the figures, the slot is configured to receive a form member that is a wide piece of dimension lumber. Those skilled in the art will appreciate that dimension lumber, such as 2×4's, 2×12's, and other sizes, are frequently used on-edge as concrete form members, especially for slabs, footings, and the like. However, it will be apparent that the present invention is not limited to the use of dimension lumber form members. Other sizes, shapes, and types of form materials can be used with the present invention. The slot 24 can be configured to receive any suitable and desired form member.

[0030] The panels that define the slot 24 may be of a variety of materials. In one embodiment, the panels are individual pieces of steel plate, and are welded together at the edges to form the slot. The steel plates could be stainless steel to resist corrosion. Alternatively, the slot could be formed of aluminum plates or other materials. Likewise, the slot could be formed of fewer members that are pressed or rolled to the desired shape. It will also be apparent that the slot could take other forms. For example, the slot shown in the figures is open on the top and one side. However, it will be apparent that the slot could have a top panel (not shown), and thus be closed on the top, thus only allowing form members to be slid horizontally into the slot from the side.

[0031] The back end panel 22 of each slot is attached, such as by welding, to the substantially vertical hinge 16. The hinge 16 includes intermeshing hinge loops 30 and 32, that are each attached, such as by welding, to the back end panels 22 of one or the other of the brackets 12 and 14. Disposed vertically through the center of the hinge loops is a cylindrical hinge pin 34. The hinge fingers are configured to slidingly rotate upon the hinge pin, allowing the angle α between the brackets to be adjusted. The form holder of the present invention can thus be used for corners of a variety of angles, and also for interconnection of form members in a straight line.

[0032] In the embodiment shown in the figures, the form holder 10 is configured to allow the angle α to vary from a minimum angle α_(min.) of about 90° to a maximum angle α_(max.) of about 270°. However, it will be apparent that a form holder according to the present invention could be configured for a wider range of angular adjustment if desired. For example, viewing FIG. 3, relatively narrow brackets 82 and 84 may be connected to a relatively large diameter hinge 86, allowing them to be rotated to a smaller minimum angle α_(min.) (smaller than 90°), and a larger maximum angle α_(max.) (larger than 270°). In order to operate in this way, the width W of each bracket may be less than half the diameter D of the hinge.

[0033] Referring back to the embodiment of FIGS. 1 and 2, given the width W of the brackets 12 and 14 and the relative diameter D of the hinge 16, when rotated to the 90° location, the back edges of the brackets draw together to create a smooth inside corner. This provides a clean, smooth appearance for the edge of the finished concrete work. However, when the form holder 10 is opened to wider angles, it will be apparent that the side of the hinge will be exposed, and the finished concrete can receive the impression of the exposed hinge 16. To solve this problem, a form insert 36 can be inserted between the back ends of the brackets. Form inserts can be configured in various sizes and angle, thus allowing a smooth corner finish for any desired angle. It will be apparent that where the appearance of the finished concrete is not important, such as concrete footings, form inserts may not be necessary.

[0034] Returning to FIG. 1, the hinge pin 34 of the hinge 16 advantageously comprises a hollow cylinder, having a central aperture 38 configured to receive a form stake 40 therethrough to affix the form holder to the ground 41 or other support surface. This configuration allows the holder to be easily positioned where desired, staked into place, adjusted to a desired angle, and the form members inserted into the brackets, for a quick, easy installation. There is thus no need to nail individual boards together at form corners, or to make miter cuts on form boards in order to create a desired angle. Depicted in FIG. 6 is a portion of a form system wherein a plurality of form holders 10 are staked into place with form stakes 40, and interconnected with form members 26. Such a system can allow a user easily to create an enclosure for footings, slabs, and the like.

[0035] Naturally, once concrete is sufficiently cured, the formwork must be removed. This can also be a time-consuming task. Advantageously, the present invention incorporates features that facilitate the removal of formwork. In one embodiment, the hinge pin 34 is removable from the hinge 16. When it is time to remove the formwork, the user may simply pull the hinge pin out of the hinge, allowing the hinge loops 30 and 32 to be pulled away from each other along with their respective brackets. In this manner, form members that are interconnected around a corner may be disconnected from each other. This sort of disassembly can also help in situations where the concrete has flowed and hardened around the irregular shape of the hinge member, thereby making it difficult to remove the adjustable form holder. When the hinge is disassembled, the parts of the holder may be separately—and probably more easily—removed from the concrete.

[0036] Another similar system could also be created where the hinge pin comprises the form stake that extends through the adjustable holder, and the holders are configured to directly pivot on the form stake. FIG. 9 is a perspective view of such a system. In this configuration, the form holder 410 comprises holders 412 and 414 that have intermeshing hinge loops 430 and 432 affixed to them. The form stake 440 extends through the center of the hinge loops, and thus performs the dual function of pivotally interconnecting the holders, and attaching the form holder 410 to the supporting surface 441 at the desired location in one operation.

[0037] Another mechanism for accommodating form removal is to make the brackets detachable from the hinge member. One embodiment of such a system is depicted in FIG. 7. The form holder 210 has brackets 212 and 214 that are not directly attached to the hinge member 216. Rather, a mounting plate 221 having key slots 223 is affixed, such as by welding, to the hinge member. The back end panels 222 of each bracket include corresponding interlocking posts 225. The interlocking posts are configured to slide into the key slots to lock the bracket to the mounting plate, and hence to the hinge member. It will be apparent that this embodiment could be oppositely configured, with the key slots disposed on the brackets, and the interlocking posts attached to the mounting plate.

[0038] The key slot locking mechanism shown in FIG. 7 is a well-known type of interconnecting mechanism. The key slots 223 include a larger diameter top end 250 and a smaller diameter bottom end 252. The interlocking posts 225 include a larger diameter head 254 and a smaller diameter shaft 256. The head of each interlocking post is configured to pass through the top end of each key slot, then slide downward so that the shaft 256 fits into the bottom end of the slot. This locks the bracket to the mounting plate 221, and also allows the bracket to be easily removed from the mounting plate by applying and upward force upon the bracket. The removable bracket 214 on the right side of FIG. 7 is shown detached from the mounting plate and hinge member, while the removable bracket 212 on the left side of FIG. 7 is shown attached to the mounting plate, with each interlocking post 225 disposed toward the bottom end of the corresponding key slot 223. It will be apparent that other mechanical connecting systems could also be employed to allow the brackets to be removably attached to the hinge member, and thereby facilitate easy removal of the forms from completed concrete work.

[0039] Another form holder system 310 with removable brackets is shown in FIGS. 8A and 8B. In this embodiment, the form stake 340 includes a plurality of vertical keyways 342, which are configured to receive key bars 344 that protrude from the back end panel 322 of each of the brackets 312, 314. As shown in FIG. 8B, the keyways in the form stake have a T-shape that is configured to slidingly mate with the T-shape of the key bars. It will be apparent that other mating shapes could be used for the keyways and key bars. The keyways may have an open bottom end and closed top end 346 for receiving the brackets before the stake is driven into the support surface, as shown in FIG. 8A. Alternatively, the keyways could have an opening at their top ends (not shown) to allow the brackets to be attached to the stake after it is driven into place.

[0040] It will be apparent that there are many ways in which the brackets can be removably attached to the form stake or to each other. Depicted in FIGS. 10A and 10B is a system wherein the form stake 540 includes a mounting ring 542. The mounting ring is configured to receive a mounting book 544 attached to the back end panel 522 of the brackets 512, 514. With this configuration, the brackets can be attached to the form stake at any angular orientation relative to each other, and are easily removable. It will be apparent that for purposes of strength and stability the form stake will preferably include more than one mounting ring and the brackets will preferably include more than one mounting hook.

[0041] The adjustable form holder of the present invention can also be used for forming walls. Obviously, any wall whose height is less than that of the holder itself can be accommodated. For the holder of FIG. 1, this implies a relatively short wall. However, viewing FIG. 4, a single form holder 110 can be made relatively tall, if desired. For purposes of this discussion, a “tall” form holder can be considered one having a total height that is more than about twelve inches high. Accordingly, the ends of taller form members 126 can be placed into the slots 124, or multiple form members 126a can be stacked in the slots to produce the desired tall wall form. As with the embodiment of FIG. 1, the tall wall form holder 110 includes holes 128 in the side panels 118 of the brackets 112 and 114 for the insertion of fasteners to hold the form members in place.

[0042] Viewing FIG. 5, as an alternative tall wall form system, multiple holders 10 according to FIG. 1 can be stacked atop each other to form a wall form holder. In this embodiment, the hinges 16 of the holders include an interconnecting mechanism for allowing axial stacking. The top end of the cylindrical hinge pin 34 includes an outer annular projection 42 that is configured to mate with a corresponding inner annular slot 44 disposed at the bottom of the hinge pin. With this configuration, individual form holders 10 can be stacked and vertically interconnected for making walls that are taller than any one form holder alone. It will be apparent that other interconnecting mechanisms can also be used to allow stacking of a plurality of adjustable form holders.

[0043] This present invention thus helps save time and effort in placing concrete forms. The form holder can be easily positioned where desired, staked into place, adjusted to a desired angle, and the form members quickly inserted and affixed therein for a quick, easy installation. It reduces the need for nailing individual boards together, or for making miter cuts.

[0044] It is to be understood that the above-referenced arrangements are illustrative of the application for the principles of the present invention. Numerous modifications and alternative arrangements can be devised without departing from the spirit and scope of the present invention while the present invention has been shown in the drawings and described above in connection with the exemplary embodiments(s) of the invention. It will be apparent to those of ordinary skill in the art that numerous modifications can be made without departing from the principles and concepts of the invention as set forth in the claims. 

What is claimed is:
 1. An adjustable form holder for concrete form members, comprising: a) a first bracket, configured to receive an end of a first elongate concrete form member; b) a second bracket, configured to receive an end of a second elongate concrete form member; and c) a hinge member, attached to the first and second brackets, configured to allow the first and second brackets to pivot relative to each other about a substantially vertical axis, so as to allow variation of a horizontal angle between the first and second brackets, and thus between the elongate form members.
 2. A form holder in accordance with claim 1, further comprising a vertical aperture, extending through the hinge member, configured to receive a form stake therethrough.
 3. A form holder in accordance with claim 2, further comprising a form stake disposed through the vertical aperture.
 4. A form holder in accordance with claim 1, wherein the first and second brackets each comprise, respectively, a substantially vertical slot defined by opposing vertical side panels and a vertical end panel, the end panel being attached to the hinge member, and the vertical slot being configured to receive the end of the respective elongate concrete form member on-edge.
 5. A form holder in accordance with claim 4, wherein the form brackets further comprise a bottom panel configured to support the end of the elongate form member.
 6. A form holder in accordance with claim 4, further comprising a securing mechanism associated with each bracket, the securing mechanism configured for securing the elongate form member to the bracket.
 7. A form holder in accordance with claim 1, further comprising elongate form members having ends disposed in the first and second brackets.
 8. A form holder in accordance with claim 7, wherein the elongate form members comprise dimension lumber, and the brackets have a height and width specifically selected to receive dimension lumber of a selected size.
 9. A form holder in accordance with claim 1, wherein the angle between the first and second brackets is adjustable between about 90° and about 270°.
 10. A form holder in accordance with claim 1, wherein the first and second brackets include a substantially vertical back edge disposed adjacent the hinge member, and the respective back edges of the first and second brackets are configured to draw together when the angle between the first and second brackets is about 90°.
 11. A form holder in accordance with claim 1, further comprising an interconnecting mechanism configured to allow vertical connection of the hinge members of adjacent form holders, so as to allow stacking of a plurality of individual form holders to accommodate the formation corners for walls that are taller than any one form holder alone.
 12. A form holder in accordance with claim 11, wherein the interconnecting mechanism comprises (1) an annular projection disposed on a first end of the hinge member of each of the plurality of form holders, and (2) a corresponding annular slot disposed on a second end of each of the plurality of form holders, the annular projection having a size suitable for mating with the annular slot.
 13. A form holder in accordance with claim 1, wherein the first and second brackets have a width, and the hinge member has a diameter, the width of the brackets being substantially less than the diameter of the hinge member.
 14. A form holder in accordance with claim 1, wherein the first and second brackets are removably attached to the hinge member.
 15. A method of placing concrete forms, comprising the steps of: a) placing an adjustable form holder at a selected location on a support surface; b) adjusting first and second pivotally connected brackets of the adjustable form holder to a selected horizontal angle therebetween; and c) placing an end of a first elongate concrete form member in the first bracket, and placing an end of a second elongate concrete form member in the second bracket, such that a horizontal angle between the first and second elongate form members is the same as the selected horizontal angle between the first and second brackets.
 16. A method in accordance with claim 15, further comprising the step of disposing a form stake through an aperture in the adjustable form holder so as to affix the form holder to the support surface.
 17. A method in accordance with claim 15, further comprising the steps of: a) placing at least one additional adjustable form holder at a selected location on the support surface; b) adjusting first and second pivotally connected brackets of the at least one additional adjustable form holder to a selected horizontal angle therebetween; c) placing ends of third and fourth elongate concrete form members in the first and second brackets, respectively, of the at least one additional adjustable form holder; and d) interconnecting the first and second elongate form members to the third and fourth elongate form members so as to create an enclosure for receiving concrete.
 18. A method in accordance with claim 17, wherein the step of interconnecting the first and second elongate form members to the third and fourth elongate form members comprises connecting the respective elongate form members to additional adjustable form holders.
 19. A concrete form system, comprising: a) a plurality of adjustable form holders, each form holder including (1) a first bracket, configured to receive an end of a first elongate concrete form member, and (2) a second bracket, configured to receive an end of a second elongate concrete form member, the second bracket being pivotally attached to the first bracket, such that a horizontal angle between the first and second brackets is pivotally adjustable; and b) a plurality of elongate form members having ends, the ends of at least some of the plurality of elongate form members being disposed in the brackets of the plurality of adjustable form holders so as to form an enclosure for receiving concrete.
 20. A concrete form system in accordance with claim 19, wherein the pivotal attachment of the first and second brackets comprises a hinge having a substantially vertical aperture, and further comprising a form stake disposed through the vertical aperture of at least one form holder to affix the form holder to a supporting surface. 